N55 Decat Downpipe (F2X & F3X)

BMW N55 4-Inch Stainless Steel Decat Downpipe | 135i 235i 335i 435i (F2X / F3X)

Strip the restriction out of your N55 and let it breathe. The Midnight Performance N55 Decat Downpipe replaces the factory catalytic converter with a 4-inch T304 stainless steel straight-through pipe — slashing backpressure, sharpening turbo response, and unlocking the aggressive exhaust character the N55 was always capable of.

Precision-engineered for the F2X and F3X chassis, this is the foundation for any serious Stage 2 or Stage 3 build.

Technical Specifications

• Material: T304 stainless steel
• Pipe diameter: 4-inch (102mm)
• Construction: Mandrel-bent, TIG welded
• Catalyst: None — straight-through decat
• Fitment: Direct bolt-on

Vehicle Compatibility

• BMW 135i — F20 / F21
• BMW 235i — F22 / F23
• BMW 335i — F30 / F31 / F34
• BMW 435i — F32 / F33 / F36

⚠️ For off-road and track use only. A Stage 2 remap is recommended after fitting. Not road legal in the UK.

Professional Installation Available

Our Birmingham workshop can fit this for you. Contact us for a quote.